Recently, the popularization of OpenID Connect as a next-generation authentication system is being expected. OpenID Connect is mainly used for user authentication for Web service users. OpenID Connect is constituted by OpenID Provider (to be referred to as an OP hereinafter) as an authentication server, UserAgent operated by a user, and Relying Party (to be referred to as an RP hereinafter) which provides services and the like the user wants to use. The use of OpenID Connect provides the following two merits. First, since various services can be used via one user account, there is no need to manage a plurality of user accounts. Second, it is possible to grant authorization to Web services provided by OpenID Provider as an authentication server of OpenID Connect in addition to authentication.
A recent multi-function peripheral allows a user to use the functions implemented in the multi-function peripheral via various types of user interfaces (to be referred to as UIs hereinafter). For example, UIs provided by a multi-function peripheral include, for example, a UI panel (to be referred to as a local UI hereinafter) mounted in the multi-function peripheral and a Web page (to be referred to as a remote UI hereinafter) which can be accessed from the Web browser of a PC connected to the multi-function peripheral via a network. As described above, since the functions of the multi-function peripheral can be used from the respective UIs, a function of performing user authentication for each UI is provided to allow user authentication without omission regardless of the UI from which access is made.
In addition, a recent multi-function peripheral allows user authentication by using an external user authentication server. Even using the authentication server makes it possible to perform user authentication for each UI (see, for example, Japanese Patent Laid-Open No. 2005-267201).
Even when OpenID Connect is used for user authentication for a multi-function peripheral, it is also desirable to perform user authentication for each UI.